Presently wireless communication devices of a given type (e.g., wireless telephones, or pagers) may be designed to operate in a variety of frequency bands depending on the jurisdiction in which the device is to be operated, and the communication protocol that is to be supported by the device. The latter necessitates the design, manufacture and maintenance of inventories of devices for each frequency band. Moreover a device that is designed to support a given frequency band and a given protocol may not be easily modified for use in a different frequency band.
Within wireless devices quartz resonators are commonly used in a system reference clock to establish the frequency of operation. Unfortunately, due to the high cost of high frequency quartz resonators it is undesirable to include multiple quartz resonators in order to support multiple bands of operation in each wireless communication device.
Recently MEMS resonators have been proposed as a low cost substitute for quartz oscillators. Unfortunately the frequencies of operation of MEMS resonators are low relative to carrier frequencies used in digital communication.
What is needed is a signal source that can generate signals at multiple frequencies.
Furthermore what is needed is multiple frequency signal source that can produce relatively high frequencies based on a low frequency reference clock